51989 has 6 divisors (see below), whose sum is σ = 60534. Its totient is φ = 44520.

The previous prime is 51977. The next prime is 51991. The reversal of 51989 is 98915.

51989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 47089 + 4900 = 217^2 + 70^2 .

It is not a de Polignac number, because 51989 - 2⁴ = 51973 is a prime.

It is a super-2 number, since 2×51989² = 5405712242, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 51989.

It is not an unprimeable number, because it can be changed into a prime (51929) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 482 + ... + 579.

It is an arithmetic number, because the mean of its divisors is an integer number (10089).

2⁵¹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

51989 is a deficient number, since it is larger than the sum of its proper divisors (8545).

51989 is a wasteful number, since it uses less digits than its factorization.

51989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1075 (or 1068 counting only the distinct ones).

The product of its digits is 3240, while the sum is 32.

The square root of 51989 is about 228.0109646486. The cubic root of 51989 is about 37.3224794837.

The spelling of 51989 in words is "fifty-one thousand, nine hundred eighty-nine".